1. Field of the Invention
The present invention concerns a parking disc for mounting on a vehicle where the parking disc is placed visible from outside, where the parking disc includes means for at least externally indicating a time for initiation of the parking, where means for indicating the time consists of an electronic display which during normal driving is connected to an electronic clock, where the display during normal driving shows the actual time and where stopping the vehicle results in switching of the display, where the display during parking constantly shows the time of initiation of the parking, and where the display by resumption of the driving is switched to the actual time, where switching of the display by resuming the driving occurs on the basis of an electric signal from at least one detector which determines an actual relative motion of the vehicle, where the switching of the display occurs after determining a minimum value for the motion of the vehicle.
2. Description of Related Art
International Patent Application Publication WO 00/75878 discloses an electronic parking disc showing actual time during operation of a vehicle, while at the initiation of parking when the ignition of the vehicle is switched off, the parking disc maintains displaying a fixed time until the next time the ignition is switched on. This prior art has both a forward facing display shaped as a normal Danish parking disc with a single pointer showing hours, and at the inner side of the parking disc there is provided a digital display so that the inwards facing clock during normal operation functions as a normal car clock. In order to ensure optimum display of actual time, the electronic parking disc contains a radio receiver for receiving a long-wave signal from a transmitter transmitting time information, or there is a receiver for receiving GPS satellite signals containing information about time.
The said parking disc has been approved by the authorities in Denmark, but in spite thereof it has various drawbacks. A substantial drawback may be that it is vehicle. Such an action is not allowed according to the common parking rules, but is almost impossible to check. I.e. traffic wardens would be sceptical of this electronic parking disc if they are aware of the possibility of cheating. Thus there may arise a number of contentious issues between traffic wardens and vehicle owners provided with electronic parking discs, as the traffic warden may assert abuse by demonstrating that the car wheels haven't been moved in spite of the parking time having been changed.
German Utility Model DE 2907726 U1 also concerns an electronic parking disc where the clock of the parking disc is satellite controlled. However, any satellite control of a clock in an electronic parking disc will not be very suited for parking in closed parking facilities without free access to open sky. I.e. parking in cellars or the lower storeys in high parking buildings will mean that no satellite signal is received.
German Patent DE 38 29 031 also includes an electronic parking disc which is activated at the absence of an ignition signal and which is deactivated by means of a detector registering, e.g., turning of engine, gearbox or wheels.